It is located in the Judean Mountains, between the Mediterranean Sea and the northern edge of the Dead Sea. If the area and population of East Jerusalem is included, it is Israel's largest city in both population and area, with a population of 763,800 residents over an area of 125.1 km2 (48.3 sq mi). Jerusalem is also a holy city to the three major Abrahamic religions—Judaism, Christianity and Islam.

During its long history, Jerusalem has been destroyed twice, besieged 23 times, attacked 52 times, and captured and recaptured 44 times. The oldest part of the city was settled in the 4th millennium BCE. In 1538, walls were built around Jerusalem under Suleiman the Magnificent. Today those walls define the Old City, which has been traditionally divided into four quarters—known since the early 19th century as the Armenian, Christian, Jewish, and Muslim Quarters. The Old City became a World Heritage site in 1981, and is on the List of World Heritage in Danger. Modern Jerusalem has grown far beyond its boundaries.

In Judaism, Jerusalem has been the holiest city since, according to the Hebrew Bible, King David of Israel first established it as the capital of the united Kingdom of Israel in c.1000 BCE, and his son, King Solomon, commissioned the building of the First Temple in the city. In Christianity, Jerusalem has been a holy city since, according to the New Testament, Jesus was crucified there, possibly in c.33 CE, and 300 years later Saint Helena identified the pilgrimage sites of Jesus' life. In Sunni Islam, Jerusalem is the third-holiest city. It became the first Qibla, the focal point for Muslim prayer (Salah) in 610 CE, and, according to Islamic tradition, Muhammad made his Night Journey there ten years later. As a result, despite having an area of only 0.9 square kilometres (0.35 sq mi), the Old City is home to many sites of tremendous religious importance, among them the Temple Mount, the Western Wall, the Church of the Holy Sepulchre, the Dome of the Rock and al-Aqsa Mosque.

Today, the status of Jerusalem remains one of the core issues in the Israeli–Palestinian conflict. During the 1948 Arab-Israeli War, West Jerusalem was among the areas captured and later annexed by Israel, while East Jerusalem, including the Old City, was captured by Jordan. Israel captured East Jerusalem during the 1967 Six-Day War and subsequently annexed it. Currently, Israel's Basic Law refers to Jerusalem as the country's "undivided capital". The international community has rejected the annexation as illegal and treats East Jerusalem as Palestinian territory held by Israel under military occupation. The international community does not recognize Jerusalem as Israel's capital, and the city hosts no foreign embassies.

According to the Palestinian Central Bureau of Statistics, 208,000 Palestinians live in East Jerusalem, which is sought by the Palestinian Authority as a future capital of a future Palestinian state.

All branches of the Israeli government are located in Jerusalem, including the Knesset (Israel's parliament), the residences of the Prime Minister and President, and the Supreme Court. Jerusalem is home to the Hebrew University and to the Israel Museum with its Shrine of the Book. The Jerusalem Biblical Zoo has ranked consistently as Israel's top tourist attraction for Israelis.